The present invention relates to a controlling apparatus for remote control operation where a master apparatus installed at a fixed location transmits a control signal to a slave apparatus placed at a remote location.
A variety of remote control apparatuses using, for example, infrared rays have been proposed where a master apparatus controls a slave apparatus at a remote location. A variety of combinations of master and slave apparatuses are possible. In this specification, the invention will be described with respect to a magnetic recording/reproducing apparatus 1 as a master apparatus and a tuner 2 as a slave apparatus separate from the magnetic recording/reproducing apparatus 1.
FIG. 11 is a perspective view of a magnetic recording/reproducing apparatus 1 and a tuner 2 to which a prior art remote control apparatus is applied. Referring to FIG. 11, the magnetic recording/reproducing apparatus 1 incorporates a light-transmitting section 3. The light-emitting section 3 transmits a light signal 5 that represents a control signal, generated in the magnetic recording/reproducing apparatus 1, for controlling the separate tuner 2. The tuner 2 incorporates a light-receiving section 4 that receives the light signal 5 transmitted from the light-transmitting section 3, and converts the light signal 5 into an electric signal. The electric signal is directed to various sections in the tuner 2. As mentioned above, the remote control apparatus is constructed of the light-transmitting section 3 and light-receiving section 4, so that the control signal is communicated between them to remotely control the tuner 2.
FIG. 12 is a cross-sectional view of the light-transmitting section 3 in FIG. 11. The light-transmitting section 3 includes a light emitting diode (referred to as LED hereinafter) 6. The LED 6 is soldered to a printed circuit board 8 fixedly held in the magnetic recording/reproducing apparatus 1, and is controlled to turn on and off in accordance with a control signal outputted from a control signal generating circuit, not shown, so as to emit a light signal 5. A housing 7 is formed with an opening therein in alignment with the LED 6 and a light-transmissive plastics panel 9 is fitted into the opening to protect the LED 6 from environment. Thus, the light signal 5 emitted from the LED 6 exits the magnetic recording/reproducing apparatus 1 through the plastics panel 9.
Commonly used LEDs emit light that travels in an area within about 60-70 degrees of its optical axis, which is the direction of maximum radiation. Thus, the light signal 5 emitted from the LED 6 travels in the air while spreading in an area bounded by the aforementioned angles.
The prior art remote control apparatus is of the construction where the light emitted within the magnetic recording/reproducing apparatus 1 exits through the plastics panel 9. Therefore, part of the light signal 5 emitted from the LED 6 is blocked by the housing 7 as shown by a hatched area R in FIG. 12. The light travels only through an area defined by an angle X1 to the outside of the housing. Therefore, the tuner 2 cannot receive the light signal 5 if the tuner 2 is located outside of the space defined by the angle X1. Thus, remote control fails.
The light-transmitting section 3 is constructed of a single LED 6 fixed in the housing 7. Installing the magnetic recording/reproducing apparatus 1 at a fixed location automatically determines the area in which the tuner can receive the light signal 5. In other words, the location of the tuner 2 is confined to a particular area determined by the location of the magnetic recording/reproducing apparatus 1.